Process of manufacturing alkali cyanids.



PATENTED DEG- 15, 1903.

' P. DANGKWARDT.

PROCESS 0F MANUFACTURING ALKALI GXANIDS.

Armonlon FILED. JUNE 1o, 190s.

N0 HOD'EL.

film *mii nl: mums PETzRs co, vncraunm.. WASHINGTON. n. c,

UNITED STATES Patented December 15, 1903.1 i

PATENT OFFICE.

PROCESS OF MANUFACTURING ALKALI CYANIDS. l

SPECIFICATION forming part of Letters-Patent No. 746,795-, datedDecember 15, 1903.

Application led J' une l0, 1903. Serial No. 160,865. (No specimens.)

To all whom t may concern:

Be it known that I, PAUL DANCKWARDT, a citizen of the United States,residing at Deadwood, Lawrence county, South Dakota, have inventedcertain new and useful Improvements in Processes of the Manufacture ofAl kali Cyanids, of vwhich the following is aspeci cation.

This invention relates to a process of producing alkali cyanide byheating a mixture of a nitrid of an alkali-earth metal, an alkali salt,and a carbid of an alkali-earth metal in an atmosphere of nitrogen. Asan alkali-earth nitrid I prefer to use magnesium nitrid, because it caneasily be' regenerated. As an alkali salt I prefer to use fluorid orsullid of sodium, and as a carbid I employ calcium carbid, though bariumcarbid or aluminium carbid may also be used.

In order to regenerate the magnesium nitrid when it is being decomposedand toavoid the addition of this substance to every newcharge, I use afurnace that has internal means for heating and is provided withsupply-pipes for the introduction of nitrogen.

In the accompanying drawings, Figure l is a vertical section of afurnace for carrying my process into effect on line 1 l, Fig. 2. Fig. 2is a horizontal section on line 2 2, Fig. l; and Fig. 3 averticalsection on line 3 3, Fig. 2.

The furnace has a shape similar to a waterjacket blast-furnace. It maybe square, oblong, or round, and is composed of a mantel ofWater-jackets a, which rest on a flreproof foundation b and are held inposition by braces and clamps c. One ofV the jackets a. has near itsbottom a tap-hole a,witb a spout d. Two opposite jackets ct haveopenings for the introduction of one or more insulated carbon blocks e,which form the resistance for the current and eifect the heating of thevinterior of the furnace. There are also in the jackets a openings forthe reception of pipes f, that supply gaseous nitrogen to the interior.

g is a cover, and h a flue connected with a stack. The due hhas a valveh for regulating the pressure of the gases Within the furnace.

In order to carry the process into effect b the above-describedapparatus, I mix the three ingredients-viz. ,an alkali-earth nitrid,

an alkali salt, and an alkali-earth carbid-in about the followingproportions, by weight: one hundred parts of magnesium nitrid,eighty-five parts of tluorid of sodium, sixtyfive parts of calciumcarbid. This mixture is filled into the furnace until the charge reachesabove the nitrogen-supply pipes f. I then fill the furnace up with amixture of only the alkali salt and the alkali-earth carbid in about thefollowing proportions, by weight: eighty-live parts of iiuorid ofsodium, sixty-five parts of calcium carbid. After the cover has been puton I start the electric current and force nitrogen into the furnace. It'magnesium nitrid, fluorid of sodium, and calcium carbid have been used,there will set in a reaction,which may be expressed by the followingformula:

As the gases of magnesium will meet the nitrogen, they will combineagain and will form magnesium nitrid. This magnesium nitrid on cominginto contact with a new charge of duorid of sodium and calciuml carbidwill again cause the first reaction, and so on.

It is important to have no oxidizing sub stances either in the charge orin the gas introduced, as that will considerably lower the output insodium cyanid. It is the nascent ,carbon and the nascent sodium oralkali metal that are to react with the magnesium nitrid. If, however,lthere would be any oxygen present, both the sodium and carbon in statunascendt' would combine with the oxy' gen and form alkali carbonateinstead of cyanid.

The product formed by my improved process-viz., a mixture of alkalicyanid and the luorid of an alkali-earth metal-isdrawn from the tap-holeet. A new charge is added from time to time to keep the furnace as fullas possible.`

The mixture of alkali cyanid and the tluorid of the alkali-earth metalmay be sold as such or refined into pure alkali cyanid by some knownprocess.

What I claim isl. The process of making alkaliccyanids, which consistsin heating a nitrid of an alkaliearth metal, a salt of an alkali metal'and a IDO phere of nitrogen, adding a mixture of an alkali-metal saltand a carbid of an alkaliearth metal,'and continuing the fusion,substantially as speciied.

Signed by me at Deadwood, South Dakota, this 4th day of June, 1903.

PAUL DAN CKWARDT.

Witnesses:

R. N. OGDEN, G. E. HAINES.

